Where's digital cable expert (ADAT)?

Kip Conner

Junior
Mar 13, 2011
370
0
0
Athens, GA
I have an Alesis HD24 and experienced an odd situation the other night during a recording. I typically use Live Wire optical cables, but was missing one so I purchased a hosa cable that has tos-link style connecter and said it was compatible with adat. When i sent audio to the recorder I was seeing 8 nice independent levels, but then when I put the recorder in record that bank of 8 when nuts. it was as if I was sending 4 pairs of stereo signals at +30dBu levels. Channels 1, 3, 5 and 7 were identical and the evens were identical. That is to say the levels on the Odds were out of control, but the same. The odds were the same matching levels.

I might not be explaining this very well!

Anyone ever experience anything like that or know why these cables don't match -other than being HOSA :)
 
Re: Where's digital cable expert (ADAT)?

Something to do with intermittent signal? Not sure why there would be a difference only when you hit record.

You can sort of test optical ADAT cables by holding one end up to a light and looking at the other end - generally they should all pass about the same brightness.
 
Re: Where's digital cable expert (ADAT)?

Did you use a wordclock cable between your micpre's or mixer and the HD24 ?
That would probably solve your problem.
 
Re: Where's digital cable expert (ADAT)?

I have an Alesis HD24 and experienced an odd situation the other night during a recording. I typically use Live Wire optical cables, but was missing one so I purchased a hosa cable that has tos-link style connecter and said it was compatible with adat. When i sent audio to the recorder I was seeing 8 nice independent levels, but then when I put the recorder in record that bank of 8 when nuts. it was as if I was sending 4 pairs of stereo signals at +30dBu levels. Channels 1, 3, 5 and 7 were identical and the evens were identical. That is to say the levels on the Odds were out of control, but the same. The odds were the same matching levels.

I might not be explaining this very well!

Anyone ever experience anything like that or know why these cables don't match -other than being HOSA :)

No funny stuff like inputs connected to outputs, creating a feedback loop?
 
Re: Where's digital cable expert (ADAT)?

No funny stuff like feedback loops and everything gets clocked by the Big Ben. My first thought it was a digital clocking issue, but after swapping the cables out it fixed it. To be honest I'm not really that well versed on all of the digital formats out there- I just buy the one that is advertised as compatible.
 
Re: Where's digital cable expert (ADAT)?

optical toslink is identical to optical adat as far as cable is concerned. The hosa isnt a great quality cable but it will work fine til its abused enough to stop working. Clocking shows up as 'ticks' that make the levels jump about half way up the meter. I dont have a good guess as to what your actual problem is, but its not the cable. You could confirm this by swapping the live wires cables and checking.
 
Re: Where's digital cable expert (ADAT)?

No funny stuff like feedback loops and everything gets clocked by the Big Ben. My first thought it was a digital clocking issue, but after swapping the cables out it fixed it. To be honest I'm not really that well versed on all of the digital formats out there- I just buy the one that is advertised as compatible.

Are you sure the HD24 was set up to accept an external clock?

I've been using an HD24 for several years with cheap RCA (brand) optical TOSLINK cables and I've never had an issue. In my experience, the build quality of TOSLINK cables does vary, but as long as the thing is not kinked or cracked any cable will work with ADAT Lightpipe. The thing to remember is that Lightpipe is just the data standard - not the cable standard. Home theater systems use S/PDIF over TOSLINK. ADAT recorders use Lightpipe over TOSLINK. The cable standards are the same.

My guess is that you had a cable or connector that was damaged in some way, or a clock problem somewhere. Posibly dust/dirt in the TOSLINK connector on the ADAT or source device.
 
Re: Where's digital cable expert (ADAT)?

Once I switched out the brand HOSA new cable with another live wire cable all worked fine. The perplexing part of the equation is why putting the machine into record caused it to get weird. I would have thought if the cable was bad it would exhibited the same issues when in input, it was almost like hitting record changed the resistance and the cable couldn't handle it. Very strange.